It is well established that specific deficiency in glycosidases is responsible for several genetic diseases including sphingolipidoses and mucopolysaccharidosis. At this moment there is no effective therapy for these inborn errors of metabolism. Our knowledge concerning the catabolism of various complex carbohydrates such as sphingoglycolipids and glycoproteins is very inadequate. In order to understand, cure and prevent those diseases due to the defect in glycosidases, it is extremely important to carefully study the nature of the glycosidases responsible for the catabolism of various complex carbohydrates accumulated in these diseases. The overall objective of this project is to isolate and study various glycosidases related to sphingolipid storage diseases and allied diseases and to use these glycosidases to study: 1) biochemical etiology of sphingolipid storage disease; 2) structure of various sphingolipids as well as complex carbohydrates accumulated in the tissue of the patient with lipid storage diseases and allied diseases; 3) to develop a model for the enzyme replacement therapy of various storage diseases due to the deficiency in glycosidase.